The goal of this proposal is to evaluate how the levels of the intermediates and enzymes of dolichol metabolism are regulated during spermatogenesis. The specific aims are to: 1) Determine and compare the levels of dolichol and dolichyl phosphate in seminiferous tubules of prepuberal rats of different ages. 2) Develop and optimize an assay for dehydrodolichyl pyrophosphate synthetase from rat testes. 3) Characterize the synthetase with respect to its substrate specificity and product character. 4) Determine and compare the levels of dolichol kinase, dehydrodolichyl pyrophosphate synthetase, dolichyl phosphate phosphatase and dolichyl phosphate dependent N-acetyl glucosaminyl transferase in homogenates and microsomes of seminiferous tubules and spermatogenic cell preparations of prepuberal rats of different ages. 5) Determine and compare the capacity of homogenates and microsomal preparations, from tubules and spermatogenic cell preparations of prepuberal rats of different ages, to incorporate sugars from nucleotide sugars into dolichyl pyrophosphate oligosaccharides and into protein and 6) Correlate any differences in the levels of the metabolites or enzymes described above with the cell types used or the emergence of different cell types in the tubules at particular phases of spermatogenesis. The methodologies to be used include radiochemical analyses of enzymes in cellular homogenates and subcellular fractions, phospholipid and glycophospholipid isolation, characterization and analysis by column and thin layer chromatography, lipid quantitation by single and double label radiochemical techniques, spermatogenic cell isolation and separation, and microscopic identification of cell types present during spermatogenesis. The proposed research applies the techniques and principles of Biochemistry to answer important developmental questions in Reproductive Biology. The studies should provide valuable information concerning the mechanism of regulation of the biosynthesis of the dolichyl derivatives required in the synthesis of the N-linked glycoproteins elaborated during spermatogenesis. An understanding of these biochemical processes associated with glycoprotein biosynthesis may have important long term implications in the understanding of autoimmunity in vasectomized and infertile men and isoimmunity in immunologic infertility in women and has potential value in the design of male contraceptives.